Can I Give My Son Montair LC Syrup 5 Hours After Administering Relent Syrup?

Hi, My son is suffering from runny nose. I have given relent syrup at 9pm as prescribes by my doctor. He also given Montair LC syrup to be given in the night time. Please confirm if I can give the montair syrup around 2 am. Is the time difference of 5hours between the 2 syrup doses ok? If not whats the best time to give Montair syrup next? Thanks